1 Field of the Invention
The present invention relates to the user interface of a computer system and, more specifically, to an improved scroll bar which allows a user to change the scroll position easily.
2 Description of the Related Art
Conventional systems provide scroll bars to facilitate scrolling of displayed data. Scroll bars allow a user to move data through a display area, thereby revealing previously hidden portions of the data. Illustrated in FIG. 1 is a typical (vertical) scroll bar used with a window. At each end of scroll bar 11 are scroll arrows 13 and 14. The scroll arrows point in the direction that the viewable portion "moves" over the data, as if the data is fixed. When a user clicks a scroll arrow, the data in the window appears to move in the opposite direction of the arrow. Along scroll bar 11, an indicator called a thumb (also called the scroll box, elevator, or slider) 12 moves to represent relatively how far the current view of the data is from the top. For example, if the current view is at the middle of the data, the thumb is in the middle of the scroll bar. This behavior of the thumb makes it a useful visual indicator for users. The user can also drag the thumb along the scroll bar to move to a different view of the data. Scrolling with a scroll bar is an easy and intuitive practice and is widely known in the art. Even though scrolling can be easy and intuitive, it is a nonessential part of the user's task and it is desirable to avoid frequent scrolling. However, users tend to repeatedly move to some particular portions of the data, or "scroll positions". For example, a user of a word processor system editing a document may wish to refer some important portions of the document repeatedly in the course of editing. In such a case, every time the user needs a reference, he or she would have to use scroll bar to view the desired portion, possibly making original portion being edited hidden, and use the scroll bar again to return to the original portion to continue editing. This method is cumbersome and unproductive, especially when repeated frequently.
Another problem with scroll bars is difficulty of returning to precisely the same position. In some cases, such as in a drawing application, scroll bar represents relatively broad range. In such cases, retaining once realized view manually is difficult, if not impossible.
Some application programs, mostly word processors or text editors, provide a function to solve these problems. This function, often called the bookmark function, allows a user to insert a "bookmark" in a location within a document and later jump back to the location. In the above example, a user can insert a "bookmark" in the frequently referred portion.
Use of this function, however, is not very intuitive. When inserting a bookmark, the user typically is prompted to input a name to identify the bookmark. It is by this name that the user specifies the bookmark when he or she wishes to go back to the position. This process has no visual indication and, in particular, has no relationship with the scroll bar, which visually represents the whole of the data.
Another problem of this prior technique is that the operation needed to invoke the function differs from application to application, making it more difficult for users to become familiar with use of this function.